.layout {
    width: 100%;
    height: 30px;
  }
  /* .split {
    padding: 30px 0;
  } */
  .aside {
    float: left;
    width: 80px;
    height: 100%;
    background-color: orange;
    color: #fff;
  }
  .main {
    overflow: hidden;
    height: 100%;
    background-color: #03a9f4;
    color: #fff;
  }
  .parent {
    background-color: orange;
    overflow: hidden;
  }
  .child {
    float: left;
    width: 100px;
    height: 30px;
    border: 1px solid #999;
  }
  /* .dem3{
    border: 1px solid red;
    overflow: hidden;
  } */
  .dem3 .a{
    border: 1px solid #999;
      margin: 10px;
  }
  .dem3 .b{
      border: 1px solid #999;
      margin: 10px;
  }
  .contain-b{
      overflow: hidden;
  }